Swinging motion of intimal flap through the aortic valve in acute aortic dissection.

ABSTRACT

The purpose of this article is to present a very rare case of Stanford type A acute aortic dissection featuring a swinging motion of the cylinder-shaped intimal flap through the aortic valve. The patient was a 62-year-old male suffering from severe cardiogenic shock. A transthoracic echocardiogram revealed aortic dissection and severe aortic regurgitation. A transesophageal echocardiogram demonstrated that the aortic dissection in the ascending aorta was circumferential and the proximal portion of the intimal flap was swinging through the aortic valve, ie., falling into the left ventricle during the diastolic phase and being ejected back into the ascending aorta during the systolic phase. An emergency graft replacement of the ascending aorta was performed. During ventricular fibrillation under total cardiopulmonary bypass, we performed cardiac massage to prevent myocardial ischemia, because blood flow from a heart lung machine inverted the intimal flap, which might have disturbed the coronary circulation. The patient's postoperative course was uneventful, and his postoperative echocardiogram revealed only a trace of regurgitant flow through the aortic valve. Back-and-forth movement of the cylinder-shaped intima requires coexistence of the following three conditions severe aortic regurgitation, circumferential dissection, and complete transection of the intimal flap. We conclude that this movement of the intimal flap should be regarded as one of the most serious complications leading rapidly to cardiogenic shock. From a surgical point of view, it is most important to prevent myocardial ischemia during cardiopulmonary bypass especially in cases in which ventricular fibrillation has occurred. We describe the ways to prevent myocardial ischemia in this rare situation.